1. Field of the Invention
This invention relates to a surgical instrument and more particularly to an instrument with the capability for continuous irrigation and evacuation of fluid into and out from a body cavity of a patient during Laparoscopic or Endoscopic surgical procedures, and for the simultaneous measurement of tissue impedance and the ablation of tissue with fixed or retractable electrodes using R.F. energy.
2. Brief Description of the Prior Art
Laparoscopic/endoscopic surgical procedure allows a surgeon to see inside the body cavity of a patient without the necessity of large incisions. This reduces the chances of infection and other complications related to large incisions. The endoscope further allows the surgeon to manipulate microsurgical instruments without impeding the surgeon""s view of the area under consideration.
During these surgical procedures it is desirable for as few lines as possible to enter the body of the patient. This reduces the size of the incision the surgeon needs to make. It follows from this that the greater the number of functions provided by a single instrument or the greater the number of instruments able to be passed through a single line entering the patient""s body, the better.
Furthermore, in certain procedures it may be desirable to irrigate the area under consideration. This in turn necessitates the evacuation of the irrigation fluid or, when bleeding has occurred, the blood or smoke or tissue residue generated by the surgical procedure.
From what has been said above it should be apparent that it is preferable for both irrigation and evacuation to be conducted along a single conduit which, also, acts as an access line for surgical instruments.
A typical device which is used in endoscopic procedures is an electrosurgical probe. Typically such a probe will comprise a radio frequency (i.e. R.F.) energy conductive tube covered with a dielectric material such as polyolefin or Teflon. At one end, for convenience called the operational end, each probe could have any one of a number of functionally shaped monopolar or bipolar electrodes. In addition a probe could have its end formed specifically for irrigation and/or evacuation.
Monopolar and bipolar electrode probes are known in the prior art. Monopolar electrode probes include a single active electrode which is surgically introduced into a body cavity and engagable with and insertable into a tissue portion of the cavity. A passive electrode is attached to the outer body surface of the patient, e.g. typically a conducting plate is adhesively attached to the patient""s leg. The body of the patient serves to complete the electrical circuit. Tissue ablation and coagulation is achieved by introducing sufficient power into the active electrode. Bipolar electrode probes include both active and passive electrodes which are similarly introduced together into the body cavity and are spaced apart from each other by a predetermined distance. Each electrode is engageable with and insertable into the tissue portion. Thus, the electrical circuit is completed by the body tissue disposed between the active and the passive electrodes and only the body tissue disposed between the two electrodes get coagulated.
In surgical operations it is often desirable to remove layers of body tissue. Such an operation can be readily performed if the affected area is totally exposed and large surgical devices can be used. However, large surgical openings are not desirable, due to the resulting bodily trauma, and exposure to the environment which increases the risk of infection. Endoscopic surgery minimizes body trauma and the risk of infection, but the devices of the prior art have significant limitations. FIGS. 29-32 show prior art devices. FIGS. 29-31 illustrate a roller ball, a flat roller bar, and a grooved roller bar respectively. These devices apply RF energy over a significant area and have proven useful for coagulating tissue to reduce bleeding, but they are not useful for tissue vaporization due to low power density. FIG. 32 shows a thin wire loop that concentrates the RF energy and is effective in cutting tissue, but does not function to coagulate, and therefore its use results in significant bleeding which makes it difficult to use in an endoscope due to the time required to remove a cutting electrode and insert a coagulation electrode, and due to the build-up of blood which then needs to be evacuated in order to view the work through the endoscope. There is clearly a need for a surgical device that can remove tissue and simultaneously coagulate the resulting exposed tissue. Use of such a device would leave the surgeon""s view unobstructed by blood, and reduce the chance of infection. As a result, more extensive and safer surgery could be performed.
Furthermore, any valves controlling the evacuation and irrigation procedures should be constructed so as to minimize the possibility of the valve malfunctions if, for example, any tissue or blood coagulates around their moving parts. Similarly if any of the instrumentation is to be reusable, such instrumentation, including the valves, should be capable of being efficiently cleaned by, for example, flushing.
U.S. Pat. No. 4,668,215 (Allgood) discloses a valve for switching between an evacuation-and an irrigation conduit and allowing both such evacuation and irrigation to be done via a single line entering the patient. The mechanism for switching between the irrigation, evacuation and closed configurations is by means of a L-valve or T-valve. This patent, in another embodiment thereof, further provides for a piston valve for making an on-off connection between an evacuation port and the line leading into the patient.
The L- and T-valves have the disadvantage that they must be manipulated by rotation by the surgeon, usually using his/her free hand. The piston valve disclosed in this patent has the disadvantage that it has many areas where blood and tissue accumulation and coagulation can occur which may result in the malfunctioning of the valve. In addition, the piston valve has numerous xe2x80x9cdeadxe2x80x9d areas where fluid flow would not occur. This precludes the device from being effectively cleaned by commonly used flushing techniques. Finally, the Allgood patent does not disclose a single body for housing an evacuation/irrigation control valve together with a housing for laparoscopic and microsurgical instrumentation.
A surgical valve that the applicant is aware of is the piston valve illustrated in FIG. 1 of the accompanying drawings.
In this valve a piston 10 is located within a cylinder 11. The piston 10 can be moved along the bore of the cylinder 11 by means of a plunger 12, from a closed position (as shown) to an open position in which a conduit 13 is aligned with an access port 14. This allows fluid flow along a path to or from access port 14, via conduit 13 and space 16 from or to a further port 15. Upon release of the plunger 12 the piston 10 returns to its closed position under action of a spring 17.
This valve, although easy to use, has the disadvantage that blood and tissue accumulation occurs in space 16 and clogs both the space and the spring 17. This may result in undesirable over-evacuation or irrigation of the patient during surgical procedures.
It is therefore an object of this invention to provide a surgical instrument which includes control means to allow for the continuous irrigation and evacuation of a body cavity of a patient during microsurgical procedures, with both irrigation and evacuation being performed along a single line into the patient. The instrument should also act as a mounting for electrosurgical probes and microsurgical instruments.
A further object of the invention is to provide a configuration for an instrument which, depending on the material it is constructed of, can be both disposable and non-disposable. In the event that the instrument is xe2x80x9creusablexe2x80x9d or xe2x80x9creposablexe2x80x9d it is an object of the invention to provide the instrument with conduits, access ports and valves which can easily be cleaned by means of commonly used cleaning techniques and conventional sterilization methods.
It is another object of the invention to provide an electrosurgical instrument with fixed or retractable RF electrodes having the capability to simultaneously perform controlled ablation of tissue using monopolar/bipolar R.F. energy and precise measurement of tissue impedance.
An object of the present invention is to provide an adjustable area of tissue coagulation, which may be larger or smaller than the size of the probe enclosing the electrodes. A further object is to provide multiple bipolar electrodes to allow a larger zone of coagulation. The spacing of the multiple electrodes may be adjusted for larger or smaller coagulation zones.
Another object of the present invention is to provide a single connecting cable system for use with an RF energy source and an RF electrode means whereby either the monopolar or bipolar output mode from the energy source may be selected and used with a single RF electrode means. The connecting cable system permits use of the single electrode means for either RF output mode (monopolar or bipolar, which are typically labelled CUT and COAG, respectively on commercially available RF generators), and the user may elect the output mode while the electrode means are in situ.
Still another object of the invention is to provide a method for hysteroscopic and laparoscopic treatment of uterine fibroids/myomas with monopolar or bipolar electrosurgical instrumentation for controlled ablation of tissue.
It is a further object of the present invention to provide an RF electrode for use with an endoscope that can cut and coagulate tissue simultaneously.
It is another object of the present invention to provide an RF electrode for use with an endoscope that can vaporize and coagulate tissue simultaneously.
It is a further object of the present invention to provide a method of cutting, coagulating and vaporization of tissue using an isotonic solution to conduct RF energy in monopolar or bipolar operation.
It is a still further object of the present invention to provide an RF electrode having non-conductive material to isolate RF energy from the endoscopic instrument resectoscope, telescope and working element.
It is a still further object of the present invention to provide a bipolar RF electrode for use with an endoscope that can resect, vaporize and coagulate tissue.
According to this invention, an endoscopic surgical instrument comprises an irrigation and an evacuation port, each port being connected through independent valves to a single access conduit; a probe connector located at one end of the access conduit, the probe connector being for receiving and retaining a hollow surgical probe; and a monopolar or bipolar radio frequency connector which exits into the access conduit in such a manner so as to make radio frequency connection with a probe received by the probe connector.
Preferably the connector for receiving an end, for convenience called the locating end, of the probe would be in the form of a receiving bore in the access conduit which would include a plurality of O-rings which provide a fluid-tight seal around the locating end of the probe. These O-rings also function to retain the probe in the receiving port while allowing the probe to be rotated. In one embodiment of the invention, the O-rings are, instead of being located within the receiving bore of the access conduit, located about the locating end of the probe.
This invention also provides for a valve, for use as either an evacuation or an irrigation valve, the valve comprising a housing, an activator connected to the housing, at least a first and a second valve access conduit, both of which exit into the housing and a fluid impervious seal mounted within the housing such that activation of the activator causes the first valve conduit to move axially relative to the seal and the second valve conduit such that the seal is disengaged and the conduits are placed in direct fluid communication with each other.
Typically, the instrument of the invention would contain two of the above described valves. One valve would act as an evacuator control while the other valve would act as an irrigation control. Both valves communicate into a single access conduit which, when the instrument is in use, continuously flows into the patient via the receiving bore and the hollow interior of the electrostatic probe.
Preferably the endoscopic surgical instrument of the invention is in the form of a pistol with the xe2x80x9cbarrelxe2x80x9d portion thereof having, at one end thereof, the receiving bore for the locating end of the endoscopic probe and, at the other end thereof, the access port for the microsurgical instruments and endoscopes.
The valves for controlling the evacuation and irrigation procedures may be mounted in the xe2x80x9chandlexe2x80x9d portion of the pistol-shaped instrument. The valves may be mounted alongside one another in the handle portion and may protrude therefrom to allow finger control by the surgeon using the instrument.
In one alternate embodiment of the invention the surgical instrument includes a housing, a single access conduit formed in the housing, an irrigation port and an evacuation port, each port being connected through independent valves to the single access conduit. The single access conduit has a first end, and a second end which is terminated in an aperture formed in the housing. A closure is provided for the aperture. A viewing device, such as an endoscope, is insertable through the aperture and into the single access conduit. The viewing device is of sufficient length such that it is extendable slightly beyond the first end. A retractable electrode assembly is also insertable through the aperture and into the single access conduit, and is of sufficient length such that it, too, is extendable beyond the first end. The retractable electrode assembly, in one embodiment, includes two retractable RF electrodes spaced apart by a predetermined width. Each RF electrode is made from a superelastic material, e.g. typically Nickel-Titanium (NiTi) metal, is sheathed within a guiding sheath, and is slidable within the sheath such that it is extendable beyond and retractable completely within the sheath. Also, each electrode is connected to a mechanism, operable by a surgeon, for moving the electrode within the sheath. Each electrode is extendable beyond its guiding sheath by a variable length and at a predetermined angle from a longitudinal axis of the single access conduit. Further, each electrode is electrically communicative with means for supplying R.F. energy and means for measuring impedance continuously on a realtime basis.
The present invention includes improved electrodes for simultaneously vaporizing, coagulating and cutting of tissue. The electrodes have a connecting end for making contact to an endoscopic device and an RF energy source. In the preferred embodiment, the construction of the electrodes is such that the connecting end joins an elongated stem having a conductive center conductor,sa majority of which is enclosed by a cover constructed from non-conductive material for the purpose of insulating the conductor from the endoscope conduit, telescope and resectoscope sheath. The cover also preferably has a saddle shaped extension, also preferably constructed of non-conductive material, for use in guiding a telescope. The conductor divides into two insulated conductive branches forming a loop at a distal end of the electrode opposite the connecting end. In a preferred embodiment, the distal end portion of the conductive loop angles away from the axial direction of the electrode, and the loop is completed with a straight conductive portion forming an axle for supporting a conductive roller thereon. The outward conductive roller surface has RF energy director points for increasing power density of RF energy coupled thereto from the conductor. The high power density vaporizes surface tissue, and simultaneously coagulates the underlying tissue as well. An alternate embodiment includes a standard loop shaped cutting electrode tip followed by a similarly shaped loop electrode with an enlargened conductor for coagulating the tissue exposed by the cutting tip.
An advantage of the present invention is the provision of an electrode that can both vaporize tissue for removal, and coagulate the underlying tissue to reduce bleeding.
A still further advantage of the present invention is a reduction in operating time because there is no need to change electrodes from a cutting electrode to a coagulating electrode.
Another advantage of the present invention is that it provides an endoscopic surgical instrument having an electrode, operable in either monopolar or bipolar mode, and with or without an isotonic solution allowing improved control over the area and volume of tissue treated, thereby eliminating the need for a conventional patient electrical return pad, reducing damage to surrounding healthy tissue.